Product Description
Normal human serum is tested for complement activity and certified to possess fully functional classical and alternative pathways of activation. Our NHS is also referred to in our product descriptions as the NHS complement standard.A functional lectin pathway is assumed to be present, but standard assays for all of its initiating components (ficolins, MASPs, and MBL) have not been established.Therefore, we have not tested specifically for lectin pathway activity.
NHS was prepared from a large number of donors.Each unit of blood was collected without anticoagulants and each was individually tested for transfusion-transmissible diseases before pooling (see Precautions/Toxicity/Hazards below).After coagulation, the liquid portion was separated by centrifugation.The different units were pooled, filtered through a 0.22 µm filter, aliqoted and frozen at -80oC.
All testing for complement activity was performed on the subsequently thawed samples to guarantee that the functional activity reported is what customers will receive when the samples are thawed.Complement activity is stable for several years if NHS is stored at -70oC or below continuously.A slight degradation of activity may be observed following additional freeze thaw cycles.
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Complement Technology的C1是级联反应中的第一个补体成分，称为补体经典途径。C1与抗原结合的抗体（免疫复合物）结合并被其激活，从而产生引发级联反应的蛋白酶。C1实际上是钙依赖性复合物中结合在一起的三种不同蛋白质（C1q，C1r和C1s）的非共价复合物。C1q通过其六个臂中的两个或多个与IgG或IgM的Fc结构域结合。多臂与免疫复合物的结合被认为会引入压力，从而导致复合物中的两个C1r蛋白（蛋白酶酶原）自身激活，从而产生两种活性的C1r丝氨酸蛋白酶（Morikis，D.和Lambris，JD（2005））。 。这些激活的C1r亚基裂解并激活复合物中的两个C1s蛋白酶酶原。活化的C1裂解补体成分C4，释放出C4a，并启动C4b与活化表面的共价连接。活化的C1也切割C2，并且C2的较大片段结合至表面附着的C4b，形成C4b，C2a，其为经典途径的C3 / C5转化酶。
